Belt joint and method of making the same



Nov. 1'2, 1929.

E. KIMMlcH' BELT JOINT AND METHODOF MAKING THE SAME F11-ed June 2,' 192e man,

ing use.

Patented Nov. l2, 1929 UNITED .STATES PATENT OFFICE ELMER G. 'KIMMICE OF AKRON, OHIO, ASSIGNOR TO THE GOODYEAR TIRE & RUBBER COMPANY, OF AKRON., OHIO, A CORPORATION OF OHIO BELT JOINT AND METHOD OF MAKING THE SAME Application iled J'une 2, 1926. Serial No. 113,144.

My invention relates to belting, and it has particular reference to means for joining or splicing power transmission belts which include a plurality of longitudinally disposed cords.

Practically all of the cord belts employed heretofore have been formed in continuous lengths, and have been utilized for purposes, such as automobile fan drives, where a belt of relatively short lengthis suitable. Cord belts have not been employed, generally, for power transmission equipment, where' the driving and driven members were materially spaced, inasmuch as this type of belting was not regarded as satisfactory for such use. However, recent improvements in the manufacture and construction of cord beltinghave rendered this product highly suitable for power transmission purposes in installations requiring the employment/'of belts of relatively long length, such, for example, as are utilized in oil well pumping installations or the like. Obviously,it is not feasible to manufacture such belts in continuous lengths, and yit is desirable', therefore, to splice or to secure the ends of the belt to each other.

The ordinary types of belt splices or securing means are not adapted for use in connection with cord belts. If the ends of the belt be overlapped and be secured by rivets, the joint thus formed is unsatisfactory for several reasons. VIn the first instance, the overlapped ends formed a rough spot in the belt, which results in considerable pounding dur- Furthermore, the fibers constituting the cords extend in the same direction, and hence, rivets, or similar securing means,

pull out quite readily. If, in a flush joint,

the cords be cut along a single line, there results azone of great weakness, for, at the line of severance of the cords, substantially all of the force transmitted must be sustained by the fabric envelope, and themselves.

It is apparent, therefore, thatI the vision of a satisfactory splice'for cord not by the cords ing presents a problem quite different from that which must be considered in connection '1 witlt leather or laminated fabric belting.

It is the object of the invention to provide -means for joining or splicing the ends of cord belting in such manner as to distribute the forces tending to' disrupt the belt, and thereby to impart to the belt a greater load transmitting capacity.

In the drawings:

Fig. 1 is a plan view of a portion of a cord belt, showing the completed splice; and

Fig. 2 is a plan view of an end of a belt that has been prepared for Splicing;

The belt, herein described to illustrate the principles of the invention, consists of an envelope of rubberized fabric which encloses a plurality of longitudinallydisposed rubberized cords 11. lAny number of fabric plies may be used in the envelo e, and likewise, the number of cords emp oyed may vary over wide limits, depending usually upon the width of the belt. Power-is transmitted primarily through the separate cords, and the fabric is employed essentially as a protective covering, rather than as a power transmission element.

Preferably, the end portion of the belt is prepared for splicing by Vcutting thev upper portion of the envelope 10 at an angle to the longitudinal axis of the belt, and in cutting away the respective plies 12 and 13, to expose a portion of each. A portion of the envelope is then removed from one side of the belt, by cutting along the edges thereof, to expose a suicient length of the cords 11. The other side of the belt at the end portion thereof is also cut at an angle to expose portions of the plies 12 and 13 in the reverse order from that followed when making lthe first cutting.

The respective cords are cut away between V are respectively indicated by the letters, a, b, c, and d. The cord b is so cut as to have ar materially greater length than the adjacent cords a and c,.but it is shorter'thanthe remote cord d. Likewise, the cords a and c lare of different lengths. The individual.

cords a are all of the same exposed length, but their ends. are spaced materially, inasmuch as the cords b, c, and ,nintervene-between any pair of cords a. f

The cords are cut at an angle'to the longii tudinal axis of thebelt, and, as illustrated,

b, c, and d, could be made of the same length and the next set of cords, a, b, c, andd, could also'bemade equal in lengthl to each other, but of a'dierent length lfrom the lirst set. ,The number of cords comprising any set need not be limited to four, vbut may be made any acceptable value.

There results, from this method of cut-- ting, a plurali of remotel spaced points of termination, within the sphce, for the respective cord elements.

The opposite end of the belt, or'thefend which is to be joined to that illustrated, is cut in such manner that when it is su rposed upon the end shown, the two parts tite snugly upon each other. Thus, the opposite end of the belt should'be formed with an exposed portion of its outer ply 12', having a length and area equal to the exposed portion of he inner ply 13. The longest .'sords of the ond endshould extend from the ends o the cords a to the edge 15 of the inner fabic p1 13. The shortest cords should be ma'de of su cient length to fill the space 'between the, ends of the' cords d and the edgfesltq -In otherl i skiled in the art, and

a firm bond of rubber is formed between the 1 cords, and it serves to secure the cords extending from either end to each other. Power is. transmitted from the cords of one end through the contactin cords of the other en to which'they are fi the-vulcanizlng process. This m e of o r` ation is more ellicient than that obtained 1n a straight cut splice or buttjoint, wherein all' of the cords are disposed end to end, and not side by side. c y

A belt. `oined in the manner described has a particularly high power transmitting ends of the belt are distributed over substantially the entire splice, and,- inasmuch as theA lencth of the' splice play bemade anyvalue desu-ed, the stress is lmposed over an appreciable portion of the belt. This stress distribution results in an increase in the power transmitting capacity of thebelt, inasmuch as the weakest portion thereof, namely, the splice, may be made to sustain a-load which approximates that which could be carried by an unbroken section.

l't will be apparent, therefore, that there is ysecuredb meanso y.

capaci. ty.' The forces which tend'to separate the provided-'a belt joint having peculiarly' de-- v sil-'able characteristics. The surface of the belt is uninterrupted, and hence, destructive pounding actions are avoided. The y of the belt at the joint is much higher than that which could be attained if rivets or like l securing means were employed, and the splice may be so dimensioned that its strength approximates ve closel the theoretical load carrying capaclty of L belt.

Many variations inf'lth'e manner of cutting the respective cords, from that shown for the pur elof illustration will occur to those hence, it is to be unwords, the exposed lengths offinfy air ofVir/OO that the invention iS not t0 be' limplyl` 13.

he two ends are treated with a coatinar of vulcanizable rubber or cement, and are tillen. superposed and are pressed firmly one, against the other. The ex sed edges of the outer plies 12 and 12" o the ends of the belt fit smigly against each other, and they are secuwd by suitable means, such as stitches` 16, which, preferably, do not extend enarely through the belt. The manner of ap t ying the stitch may be varied, but it is referred to employ the method described an claimed in my co-pending application for a belt joint, No. 59,845, filed October 1, 1925. The splice is then vulcanized under pressure, to form a continuousbelt having a smooth and uninterru ted surface. v

t will be'observed that, in the splice ilsl lustrated, the cords of either end are' so disposed that they are interposed, for a portion of their length, with the cords extending from the opposite end. Upon vulcanization,

tions of the cords so that the ends thereo allen staggered, forming a similar configuration"v at another end, coating the ends with vul` canizable rubber, superposing the ends and vulcanizing the joint.

2. An article of manufacture comprising a splice for joining the ends of rubberized fablas.

posed 7 `upon the invention as are set forth in the folric and scgrd belts, one end of the belt havingY s portion f the ends of the cords so removed that the-ends are staggered, the other end of the belt similarly havin su rposed ,in' complemen relation an ru ber on the end portionsbaflr'te cords fbl retaining the ends of the belt (together.

end rtiens ofjts cords removed, said enof e belts 3. An article of manufacture comprising a splice for joining the ends of rubberized fabric and cord belts, one end of the belt having portions of the ends of the cords so removed that the ends are staggered and disposed in lines diagonal to the length of the belt, the other end of the belt similarly having end portions of its cords removed, said ends of the belts being superposed in complementary relation, and rubber on the end portions of the cords for retaining the ends of the belt tovulcanizable rubber compound,superposing the ends and vulcanizing the joint.

In witness whereof, I have hereunto signed my name.

ELMER G. KIMMICH. 

